A vehicle barrier system comprises a housing, substantially vertical members, a barrier member, and an actuation assembly. The barrier member is coupled with the substantially vertical members. The barrier member is configured to stop a moving vehicle when the substantially vertical members are in a raised position relative to the housing. The actuation assembly is operable to selectively raise and lower the substantially vertical members relative to the housing to selectively deploy and retract the barrier member relative to the housing. The actuation assembly comprises a powered rotary actuator mounted to the barrier member. The actuation assembly is operable to convert rotary motion from the rotary actuator into linear movement of the barrier member. A counterweight provides opposing mass and vertical motion relative to the barrier member.